A method executes a preempt by a standby database appliance in a high-availability active/active appliance cluster. The appliance cluster includes a transaction processing standby group and a persistent storing standby group. The transaction processing standby group includes a primary active appliance and a standby appliance. One or more processors receive a Hello message from the primary DB appliance. The processor(s) examine a priority field in the Hello message, in order to determine a priority of the standby database appliance according to the persistent state to thereby determine whether the standby database appliance requests a preempt, where the persistent state includes a state of an application and a database of the primary DB appliance. The processor(s) implement a failover in response to the preempt request to thereby take over a duty of the primary DB appliance.